code: def _get_vhost(self, party: PartyMeta):
      low, high = (
          (self._party, party)
          if self._party < party
          else (party, self._party)
      )
      vhost = f"{self._session_id}-{low.role}-{low.party_id}-{high.role}-{high.party_id}"
      return vhost
  
imports: import json
  from logging import getLogger
  from typing import List, Optional
  from fate.arch.federation.api import PartyMeta
  from fate.arch.federation.message_queue import MessageQueueBasedFederation, Party
  from ._mq_channel import MQChannel
  from ._rabbit_manager import RabbitManager
label_desc: Use image node_id 5 for calling the RabbitmqFederation obj's underlying member method code with example usage: obj._get_vhost(party) and returns: vhost